CARBON CAPTURE SYSTEM AND METHOD FOR CAPTURING CARBON DIOXIDE

Description

TECHNICAL FIELD

[0001] The present invention relates to a carbon capture system and method for capturing carbon dioxide.

[0002] Several systems and methods have been described previously which detail the capture of CO₂ from flue gas. These systems and methods can be integrated into different applications, such as into an industrial application or into a power plant to capture carbon dioxide from flue gas. Due to the rapid deactivation of natural sorbent materials, such as limestone, a preferred and particularly advantageous application of the present system and method are in connection with the production of low carbon content feed material for downstream cement clinker production, such as in a rotary kiln. While in the following description particular advantage of the proposed scheme for cement production is made, it is anyhow clear that the application of the system and method are not limited to cement production.

BACKGROUND

[0003] Cement production occurs by clinkering a raw material typically including limestone CaCO₃ (as a source of calcium oxide CaO), and clay, marl or shale (as source of SiO₂, Al₂O₃, Fe₂O₃) and typically also other materials such as sand.

[0004] A coupled carbon capture and cement production occurs, as for example described in US2009/025544A1 over the following steps:

1) Sorbent preparation; material milling and heat-treatment, such as the calcination of limestone to produce CaO (allowing capture of the chemically associated CO₂ during calcination in the Calciner reactor);

2) Exposure of the sorbent powder to flue gas (possibly generated for the above mentioned heat treatment but also possibly from an external process) in order to convert CaO to CaCO₃ by lowering the concentration of CO₂ in the combustion flue gas through gas solid contact in the Carbonator reactor;

3) Regeneration of the sorbent materials, in particular the restoration of the CO₂ capture capacity (quantity CO₂ / quantity sorbent);

4) A sorbent purge to close the material balance of the cycle and remove deactivated sorbent from the system which is utilized for cement production.

[0005] Considering the above steps, Figure 1 shows a simplified block flow diagram representing a state of the art process scheme for cement production coupled with a carbon dioxide capture process as shown in US2007/0032380A1. It includes a Calciner 1, a Carbonator 2 and a kiln 3. Raw material containing limestone CaCO₃ is supplied from a raw material supply 4 into the Calciner 1 where the make-up sorbent (mainly CaCO₃) is calcined (decomposed by heat) along with CaCO₃ from the Carbonator according to the reaction

        CaCO₃ → CaO + CO₂

generating carbon dioxide CO₂ and carbon dioxide lean sorbent CaO. The lean sorbent CaO is supplied to the Carbonator 2 where carbon dioxide CO₂ is captured from flue gas 5 according to the carbonation reaction

        CaO + CO₂ → CaCO₃.

[0006] Gas 6 deprived from carbon dioxide CO₂ is discharged from the Carbonator 2. The calcium carbonate CaCO₃ generated at the Carbonator 2 is supplied back into the Calciner 1 allowing the release of captured Carbon dioxide and sorbent regeneration.

[0007] The carbon containing flue gas 5 may be attributed to a variety of thermally driven processes, such as power generation but a quantity of the flue gas will always be attributed to the cement process. At the kiln 3 flue gas is generated by combustion of a fuel with air; in addition carbon dioxide CO₂ is released during the clinkering reactions due to the residual carbon content of the feed material leaving the Carbonator 2 on route to the Kiln 3.

[0008] Figure 6 shows that after some adsorption/desorption cycles, the calcium oxide CaO loses its capacity to adsorb carbon dioxide CO_2; for this reason it must be purged.

[0009] According to the scheme of figure 1, purging is made by discharging calcined raw material containing calcium carbonate CaCO₃ from the Carbonator 2 and supplying it to the kiln 3 for calcination and thus clinkering.

[0010] As mentioned this scheme has the drawback that calcium carbonate CaCO₃ formed in the Carbonator is calcined at the kiln 3 which requires additional fuel combustion and produces additional CO₂ associated with the chemically bound CO₂ captured from the flue gas at the Carbonator 2. This causes an unnecessary carbon dioxide circulation between the Kiln and the Carbonator and consequently increased energy consumption and equipment dimensions and costs.

[0011] Figure 2 shows a second simplified block flow diagram representing a state of the art process scheme for cement production as disclosed in US2009/0255444 A1. It is similar to the scheme of figure 1 and same numbers indicates same or similar components. The scheme of figure 2 differs from the scheme of figure 1 in that purging is made by discharging raw material containing calcium oxide CaO from the Calciner 1 and supplying it to the kiln 3.

[0012] This second scheme reduces the amount of circulating carbon dioxide, because a reduced amount of carbon dioxide is released at the kiln (because additional calcination of CaCO₃ associated with carbon dioxide captured from the flue gas is avoided); nevertheless fresh and highly active calcium oxide CaO (sorbent) that can be most efficiently used for carbon capture is purged unselectively together with deactivated or spent sorbent (i.e. sorbent that has a reduced capacity to adsorb carbon dioxide).
An alternative to the first and second scheme without a kiln is discussed in US 2010/0086456 A1.

SUMMARY

[0013] An aspect of the invention includes providing a system and a method that improve sorbent activity by avoiding or at least reducing unselectively purging of fresh and highly active sorbent and at the same time limit the circulation of carbon dioxide.

[0014] These and further aspects are attained by providing a system and a method in accordance with the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Further characteristics and advantages will be more apparent from the description of a preferred but non-exclusive embodiment of the system and method, illustrated by way of non-limiting example in the accompanying drawings, in which:

Figures 1 and 2 show examples of state of the art process schemes for Carbon capture coupled with cement production;

Figure 3 shows a simplified block flow diagram representing a process scheme for carbon capture coupled with cement production according to the invention;

Figure 4 shows a more detailed block flow diagram of an integrated carbon capture solution for cement production;

Figure 5 is diagram showing the fraction of sorbent in the system having completed a given number of calcination and recarbonation cycles. Figure 5 represents the situation for the plant schemes of figure 2 (curve A) and figure 3 (curve B) considering the material flows required to decarbonize cement production using the above mentioned methods;

Figure 6 is a diagram showing the reduction of sorbent activity with an increasing number of calcination and recarbonation cycles.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0016] With reference to figure 3, it shows a carbon capture system comprising a first Calciner 1 and a Carbonator 2.

[0017] The Carbonator 2 is for adsorbing carbon dioxide from flue gas by employing a lean sorbent in order to generate a more rich sorbent.

[0018] The composition of the lean and rich sorbent is dependent on system design and system operational parameters (such as the ratio of make-up flow to recirculation flow) in addition to the deactivation characteristic of the material. For deactivated rich sorbent the mole fraction of CO₂ bound to available Ca in the particle is typically less than 0.2 (corresponding to between 10 and 20 sorbent cycles in figure 6.

[0019] In the following reference to CaO as the carbon dioxide lean sorbent and CaCO₃ as the carbon dioxide rich sorbent is made; other lean/rich sorbent can anyway be used. In addition it is clear that lean and rich sorbent is not made of only CaO and CaCO₃ but they are mixtures including mainly CaO or CaCO₃ and other materials; for example the lean sorbent has CaO as the main component, but may also contain CaCO₃ and similarly the rich sorbent may also contain CaO.

[0020] The first Calciner 1 is for desorbing the carbon dioxide rich sorbent CaCO₃ from the carbon dioxide CO₂ generating the carbon dioxide lean sorbent CaO.

[0021] The first Calciner 1 has a supply 4 of raw material to be calcined and a connection 13 between the first Calciner 1 and the Carbonator 2 for transferring the calcined raw material including the carbon dioxide lean sorbent CaO to the Carbonator 2.

[0022] In addition, the system has a second Calciner 15 for desorbing a carbon dioxide rich sorbent CaCO₃ from carbon dioxide CO₂ generating a carbon dioxide lean sorbent CaO, and connections 16 and 17 between the Carbonator 2 and the second Calciner 15.

[0023] The connection 16 between the Carbonator 2 and the second Calciner 15 is for transferring the carbon dioxide rich sorbent CaCO₃ to the second Calciner 15, and the connection 17 between the second Calciner 15 and the Carbonator 2 is for transferring carbon dioxide lean sorbent CaO back to the Carbonator 2 for renewed capture of carbon dioxide CO₂.

[0024] The system can be used in a number of different applications, for this reason the Carbonator 2 can be supplied with flue gas containing carbon dioxide CO₂ to be captured and separated from the flue gas.

[0025] Preferably, the system is used in a cement production plant; for this reason there are also provided a kiln 3 for cement production and a connection 18 between the second Calciner 15 and the kiln 3 for transferring carbon dioxide lean sorbent CaO to the kiln 3.

[0026] Application of the system in a plant for cement production is particularly advantageous because in this case the amount of make-up CaCO₃ (supplied with fresh raw material) is very high compared to the amount of purged CaO (forwarded to the kiln) . This can be shown with reference to the ratio of make-up molar sorbent flow to the molar sorbent circulation rate, defined by

[0027] Ratio = Moles of CaO obtained by calcining the make-up sorbent (mainly CaCO₃) / Moles of sorbent (mostly CaO) required to capture CO₂ from a given flue gas.

[0028] The ratio is typically above 1 for the schemes described in Figure 1-2, and is well below 1, typically less than 0.05, for post combustion carbon dioxide capture (for example in power plants or industrial applications). Anyhow, the system provides benefits also for applications to industrially generated flue gas or flue gas from power generation.

[0029] Figures 4 shows the system in more detail; this system can for example be applied as a carbon capture retrofit solution for an existing cement plant; when describing this figure reference to CaO and CaCO₃ is made as one of the main components used in cement production and as the preferred sorbent. It is clear that in applications different from cement production the sorbent can be any appropriate natural or synthetic sorbent.

[0030] Figure 4 shows a raw material supply 4 (for e.g. raw meal containing CaCO₃) connected to one or more preheaters 21, 22; for example the preheater 21 represents a number of preheaters (for example four or five preheaters from an existing cement plant) for the raw material to be calcined. The preheater 21 heats the raw material by cooling a mixture of carbon dioxide rich flue gas originating from the kiln 3 via a line 23 and carbon dioxide lean flue gas from the Carbonator 2 via a line 24. For example, the kiln gas is bypassed to the preheater 21 of the existing plant to ensure the required operating pressure (under atmospheric pressure, vacuum conditions).

[0031] The preheater 22 heats the raw material by cooling the carbon dioxide discharged from the first and second Calciners 1 and 15 via the lines 29, 30.

[0032] The preheater 22 is connected to the first Calciner 1 for supplying the raw material (preheated raw material).

[0033] Between the first Calciner 1 and the Carbonator 2, a solid/solid heat exchanger 31 is provided, for heating the carbon dioxide rich sorbent CaCO₃ moving from the Carbonator 2 to the second Calciner 15 by cooling the carbon dioxide lean sorbent CaO moving from the first Calciner 1 and/or the second Calciner 15 to the Carbonator 2.

[0034] The second Calciner 15 is connected with the kiln 3 via the connection 32 and with the Carbonator 2 via the connection 33.

[0035] In addition, preferably a separator 34 is provided connected on the line 23, between the kiln 3 and the preheater 21; the separator 34 separates the solid particles possibly contained in the flue gas from the kiln 3 and forwards them back to the kiln 3 via a line 52.

[0036] In order to heat the first and second Calciners 1 and 15, a furnace 35 (for example air fired furnace) is provided; the furnace 35 heats solids that are circulated via connection lines 36 between the furnace 35 and the first Calciner 1 and via connection lines 38 between the furnace 35 and the second Calciner 15. Naturally also different schemes are possible for heating the Calciners 1 and 15. For example each Calciner 1, 15 can have a furnace or indirect heat transfer schemes without solids circulation, or direct fired (oxy-fuel) calcination can be implemented.

[0037] A connection 39 is provided between the furnace 35 and the Carbonator 2, for supplying flue gas generated in the furnace 35 by combusting a fuel into the Carbonator 2. Preferably, a heat exchanger 40 is provided on the connection 39, for preheating the air (or oxidizer) supplied into the furnace 35 via a line 42 by cooling flue gas discharged from the furnace 35 via the line 39; an additional line 43 can be provided to supply preheated air (or oxidizer, generated from cooling clinker exiting the kiln 3) to the furnace 35, bypassing the heat exchanger 40.

[0038] A heat exchanger 45 is also preferentially provided in addition to or in place of the heat exchanger 40, in order to preheat solids supplied via a line 46 to the furnace 35 by cooling the flue gas discharged from the furnace 35 via the line 39. The preheater 45 functions in a counter current manner heating the hot solids which enter at the top via line 46 and fall via gravity through the rising cooling flue gas from furnace 35. The line 46 can originate from the line 36 forwarding solids from the Calciner 1 into the furnace 35 and/or from the line 38 forwarding the solids from the calciner 15 into the furnace 35.

[0039] The kiln 3 is connected to a heat exchanger 48 for cooling the clinker 49 discharged from the kiln 3 by heating the fresh oxidizer such as air; the heat exchanger 48 is then connected via the connections 42, 43 to the furnace 35 for supplying the heated air (or oxidizer) into the furnace 35, and via a connection 50 to a fuel drying system, for drying solid fuel such as coal. The fuel drying system is then connected to the furnace 35 and kiln 3 in order to supply the required fuels.

[0040] The operation of the system is apparent from that described and illustrated and is substantially the following.

[0041] Raw material supply 4 supplies raw material to the preheaters 21 and 22 where it is heated and then supplied to the first Calciner 1. At the first Calciner 1 raw material is calcined (for example raw meal for cement production, it can be different for different applications). Since the raw material supplied to the first Calciner is fresh raw material additional time is required to calcine the sorbent. The Calciner 1 is designed accordingly so that the conversion CaCO₃ into CaO is almost complete (i.e. almost all CaCO₃ is converted into CaO). This conversion occurs according to the calcination reaction

        CaCO₃ → CaO + CO₂

usually at a temperature above 900°C, preferably about slightly above 900°C.

[0042] The CaO is supplied to the Carbonator 2 where it adsorbs carbon dioxide from the flue gas coming from the furnace 35 (and possibly from flu gas generated in an industrial application or power plant); adsorption takes place according to the reaction

        CaO + CO₂ → CaCO₃

usually at a temperature between about 600-750°C.
at the heat exchanger 31 CaO moving from the first Calciner 1 to the Carbonator 2 is cooled against rich sorbent CaCO₃ moving from the Carbonator 2 to the second Calciner 15; Rich sorbent CaCO₃ is thus forwarded to the second Calciner 15.

[0043] At the second Calciner 15 carbon dioxide is released by thermal decomposition according to the calcination reaction

        CaCO₃ → CaO + CO₂

usually at a temperature above 900°C, preferably about slightly above 900°C.

[0044] CaO is thus supplied to the kiln 3 via the line 32 and partly to the Carbonator 2 via the line 33.

[0045] Since at the Carbonator 2 there is a large amount of CaO coming from the first Calciner 1 (this is fresh CaO) and the amount of CaO from the second Calciner 15 is limited (because CaO is only purged from the second Calciner 15), the carbonation reaction at the Carbonator 2 is very efficient and the CaO can adsorb a large amount of carbon dioxide.

[0046] Figure 5 shows the cycles that the CaO has undergone in a system according to figure 2 (curve A) and according to figures 3 and 4 (curve B). This figure shows that according to the invention (figures 3 and 4) the CaO supplied to the Carbonator 2 undergoes less calcination / carbonation cycles and is therefore more reactive.

[0047] Considering the decline in the activity of the sorbent according to figure 6, the method of the invention provides an increased active fraction of circulating sorbent for the same sorbent molar flow (molar flow of CaO and CaCO₃). Considering the make-up rate of fresh sorbent (required for cement production), the method shown in figure 3 increases sorbent activity (mol CaCO₃/ mol CaO and CaCO₃ in the sorbent) by between 5 to 20%, typically above 10%. Ultimately this translates into a lower required sorbent circulation rate or smaller equipment.

[0048] The furnace 35 combusts a fuel and generates hot solids that are circulated via lines 36 and 38 between the furnace 35 and the first and second Calciners 1 and 15. Preferably a part of the cooled solids returning from the Calciners (1 or 15) is diverted via the line 46 to be heated against flue gas discharged from the furnace 35 in the heat exchanger 45. The flue gas discharged from the furnace 35 is supplied into the Carbonator 2 (for carbon dioxide capture) after cooling via the heat exchangers 45 and 40.

[0049] The carbon dioxide rich flue gas from the kiln 3 is supplied to the separator 34 via the line 23, where solid particles are separated from the gas and forwarded back to the kiln 3 via the line 52.

[0050] The present invention also refers to a method for capturing carbon dioxide.

[0051] The method comprises supplying a raw material containing a carbon dioxide rich sorbent such as CaCO₃ (but other sorbents are possible, CaCO₃ is preferably used when the method is implemented in connection with a kiln for cement production) into a first Calciner 1. At the first Calciner 1, the raw material is calcined according to the calcination (decarbonation reaction)

        CaCO₃ → CaO + CO₂

that usually takes place at a temperature above 900°C, preferably about slightly above 900°C.

[0052] Following the calcination reaction, a calcined raw material containing a carbon dioxide lean sorbent CaO is generated; in addition, also carbon dioxide is generated.

[0053] The calcined raw material containing the carbon dioxide lean sorbent CaO is supplied to the Carbonator 2. In addition, also flue gas is supplied into the Carbonator 2; the flue gas comes from the furnace 35, but in other applications can also come from an industrial process or a furnace of a power plant for electricity production.

[0054] At the Carbonator 2, carbon dioxide from flue gas is adsorbed by the carbon dioxide lean sorbent CaO according to the carbonation reaction

        CaO + CO₂ → CaCO₃

that takes place at a temperature between about 600-750°C.

[0055] Following the carbonation reaction, a raw material containing a carbon dioxide rich sorbent CaCO₃ is generated.

[0056] The raw material containing carbon dioxide rich sorbent, namely CaCO₃, is in turn supplied to the second Calciner 15.

[0057] At the second Calciner 15, the raw material containing carbon dioxide rich sorbent CaCO₃ is calcined according to the calcination (decarbonation reaction)

        CaCO₃ → CaO + CO₂

that usually takes place at a temperature above 900°C, preferably about slightly above 900°C.

[0058] Following the calcination reaction, calcined raw material containing carbon dioxide lean sorbent CaO and carbon dioxide are generated.

[0059] A part of the calcined raw material containing carbon dioxide lean sorbent CaO is supplied to the Carbonator 2.

[0060] When the method is used in connection with a kiln for cement production (preferred application) a part of the calcined raw material containing carbon dioxide lean sorbent CaO is transferred from the second Calciner 15 to the kiln 3 for cement production.

[0061] The additional Calciner 15 provides increased flexibility to consider increased calcination times ensuring complete calcination of make-up sorbent and ultimately increasing the sorbent activity (quantity CO₂ / quantity sorbent).

[0062] Naturally the features described may be independently provided from one another.

[0063] In practice the materials used and the dimensions can be chosen at will according to requirements and to the state of the art.

REFERENCE NUMBERS

[0064] 

1 Calciner

2 Carbonator

3 kiln

4 raw material supply

5 flue gas

6 gas deprived from carbon dioxide

13 connection

15 second Calciner

16 connection

17 connection

18 connection

21 preheater

22 preheater

23 line

24 line

29 line

30 line

31 heat exchanger

32 connection

33 connection

34 separator

35 furnace

36 connection line

38 connection line

39 connection

40 heat exchanger

42 line

43 line

45 heat exchanger

46 line

48 heat exchanger

49 clinker

50 connection

52 line

A cycles that the CaO has undergone in a system according to figure 2

B cycles that the CaO has undergone in a system according to figures 3 and 4

Claims

1. A carbon capture system comprising
a Carbonator (2) configured to adsorb carbon dioxide using a first carbon dioxide lean sorbent (13) and a second carbon dioxide lean sorbent (17)to generate a carbon dioxide rich sorbent (16),
a supply of raw material (4) containing a carbon dioxide rich sorbent,
a first Calciner (1) configured to calcine the supply of raw material (4) by thermally decomposing, into the first carbon dioxide lean sorbent (13) and
a first carbon dioxide amount, a connection (13) between the first Calciner (1) and the Carbonator (2) for transferring at least the first carbon dioxide lean sorbent to the Carbonator (2),
characterised by further comprising
a second Calciner (15) configured to thermally decompose the carbon dioxide rich sorbent (16) generated in the Carbonator into carbon dioxide lean sorbent and a second carbon dioxide amount, a connection (16) between the Carbonator (2) and the second Calciner (15) for transferring at least the carbon dioxide rich sorbent to the second Calciner (15),
a connection (17) between the second Calciner (15) and the Carbonator (2) for transferring the second carbon dioxide lean sorbent (CaO) to the Carbonator (2) and means (18) for drawing a purge stream of carbon dioxide lean sorbent from the second Calciner.

2. A carbon capture system of claim 1, characterised by further comprising
a kiln (3) for cement production,
a connection (18) between the second Calciner (15) and the kiln (3) for transferring the purge stream of carbon dioxide lean sorbent to the kiln (3).

3. A carbon capture system of claim 1, characterised by further comprising a preheater (21, 22) for the raw material to be calcined.

4. A carbon capture system of claim 1, characterised by further comprising a solid/solid heat exchanger (31) for heating the second carbon dioxide rich sorbent moving from the Carbonator (2) to the second Calciner (15) by cooling the first and the second carbon dioxide lean sorbent moving from the first Calciner (1) and the second Calciner (15) respectively to the Carbonator (2).

5. A carbon capture system of claim 2, further comprising a heat exchanger (48) for cooling clinker discharged from the kiln (3) by heating fresh oxidizer, and at least a connection (42, 43) of the heat exchanger (48) to at least one of:

- the furnace (35), for supplying the heated oxidizer into the furnace (35),

- a fuel drying system.

6. A carbon capture system of claim 5, wherein at least one of the connections (42) to the furnace (35) is provided with a heat exchanger (40) for preheating the oxidizer supplied into the furnace (35) by cooling flue gas discharged from the furnace (35).

7. A method for capturing carbon dioxide comprising supplying a first raw material containing a first carbon dioxide rich sorbent into a first Calciner (1),
at the first Calciner (1), thermally decomposing the first carbon dioxide rich sorbent into a first carbon dioxide lean sorbent and a first carbon dioxide amount, supplying the calcined first raw material containing the first carbon dioxide lean sorbent to a Carbonator (2),
at the Carbonator (2), adsorbing a carbon dioxide from flue gas generating a second raw material containing a carbon dioxide rich sorbent, characterised by
supplying the second raw material containing the second carbon dioxide rich sorbent into a second Calciner (15),
at the second Calciner (15), thermally decomposing the second carbon dioxide rich sorbent into a second carbon dioxide lean sorbent and a second carbon dioxide amount, transferring a part of the calcined second raw material containing the second carbon dioxide lean sorbent to the Carbonator (2) and drawing from the second Calciner as purge stream the other part of the calcined second raw material.

8. The method of claim 7, characterised in that the first and the second carbon dioxide rich sorbent includes CaCO₃ and the first and the second carbon dioxide lean sorbent includes CaO.

9. The method of claim 7, characterised by transferring the other part of the calcined second raw material containing the second carbon dioxide lean sorbent from the second Calciner (15) to a kiln (3) for cement production.

Ansprüche

1. Kohlenstoffabscheidungssystem, umfassend
einen Karbonator (2), der dafür gestaltet ist, unter Verwendung eines ersten kohlendioxidarmen Sorptionsmittels (13) und eines zweiten kohlendioxidarmen Sorptionsmittels (17) Kohlendioxid zu adsorbieren, um ein kohlendioxidreiches Sorptionsmittel (16) zu erzeugen,
eine Zufuhr von Ausgangsmaterial (4), das ein kohlendioxidreiches Sorptionsmittel enthält,
einen ersten Kalzinator (1), der dafür gestaltet ist, die Zufuhr von Ausgangsmaterial (4) durch thermische Zersetzung zu dem ersten kohlendioxidarmen Sorptionsmittel (13) und einer ersten Menge Kohlendioxid zu kalzinieren,
eine Verbindung (13) zwischen dem ersten Kalzinator (1) und dem Karbonator (2) zum Überführen wenigstens des ersten kohlendioxidarmen Sorptionsmittels zu dem Karbonator (2),
dadurch gekennzeichnet, dass es ferner umfasst:

einen zweiten Kalzinator (15), der dafür gestaltet ist, das in dem Karbonator erzeugte kohlendioxidreiche Sorptionsmittel (16) thermisch zu einem kohlendioxidarmen Sorptionsmittel und einer zweiten Menge Kohlendioxid zu zersetzen,

eine Verbindung (16) zwischen dem Karbonator (2) und dem zweiten Kalzinator (15) zum Überführen wenigstens des kohlendioxidreichen Sorptionsmittels zu dem zweiten Kalzinator (15),

eine Verbindung (17) zwischen dem zweiten Kalzinator (15) und dem Karbonator (2) zum Überführen des zweiten kohlendioxidarmen Sorptionsmittels (CaO) zu dem Karbonator (2), und Einrichtungen (18) zum Ziehen eines Spülstroms von kohlendioxidarmem Sorptionsmittel aus dem zweiten Kalzinator.

2. Kohlenstoffabscheidungssystem gemäß Anspruch 1, dadurch gekennzeichnet, dass es ferner umfasst:

einen Ofen (3) für die Zementherstellung,

eine Verbindung (18) zwischen dem zweiten Kalzinator (15) und dem Ofen (3) zum Überführen des Spülstroms von kohlendioxidarmem Sorptionsmittel zu dem Ofen (3).

3. Kohlenstoffabscheidungssystem gemäß Anspruch 1, dadurch gekennzeichnet, dass es ferner einen Vorheizer (21, 22) für das zu kalzinierende Ausgangsmaterial umfasst.

4. Kohlenstoffabscheidungssystem gemäß Anspruch 1, dadurch gekennzeichnet, dass es ferner einen Fest/Fest-Wärmetauscher (31) zum Erhitzen des zweiten kohlendioxidreichen Sorptionsmittels, das sich von dem Karbonator (2) zu dem zweiten Kalzinator (15) bewegt, durch Kühlen des ersten und des zweiten kohlendioxidarmen Sorptionsmittels, die sich von dem ersten Kalzinator (1) bzw. dem zweiten Kalzinator (15) zu dem Karbonator (2) bewegen, umfasst.

5. Kohlenstoffabscheidungssystem gemäß Anspruch 2, ferner umfassend einen Wärmetauscher (48) zum Kühlen von Klinker, der aus dem Ofen (3) abgeführt wird, durch Erhitzen von frischem Oxidationsmittel, und wenigstens eine Verbindung (42, 43) des Wärmetauschers (48) zu wenigstens einem von:

- dem Brennofen (35), zum Zuführen des erhitzten Oxidationsmittels in den Brennofen (35),

- ein Brennstofftrocknungssystem.

6. Kohlenstoffabscheidungssystem gemäß Anspruch 5, wobei wenigstens eine der Verbindungen (42) zu dem Brennofen (35) mit einem Wärmetauscher (40) zum Vorheizen des Oxidationsmittels, das dem Brennofen (35) zugeführt wird, durch Kühlen von aus dem Brennofen (35) ausgestoßenem Rauchgas ausgestattet ist.

7. Verfahren zum Abscheiden von Kohlendioxid, umfassend Zuführen eines ersten Ausgangsmaterials, das ein erstes kohlendioxidreiches Sorptionsmittel enthält, in einen ersten Kalzinator (1),
in dem ersten Kalzinator (1) thermisches Zersetzen des ersten kohlendioxidreichen Sorptionsmittels zu einem ersten kohlendioxidarmen Sorptionsmittel und einer ersten Menge Kohlendioxid,
Zuführen des kalzinierten ersten Ausgangsmaterials, das das erste kohlendioxidarme Sorptionsmittel enthält, zu einem Karbonator (2),
in dem Karbonator (2) Adsorbieren von Kohlendioxid aus Rauchgas, um ein zweites Ausgangsmaterial, das ein kohlendioxidreiches Sorptionsmittel enthält, zu erzeugen,
gekennzeichnet durch
Zuführen des zweiten Ausgangsmaterials, das das zweite kohlendioxidreiche Sorptionsmittel enthält, in einen zweiten Kalzinator (15),
in dem zweiten Kalzinator (15) thermisches Zersetzen des zweiten kohlendioxidreichen Sorptionsmittels zu einem zweiten kohlendioxidarmen Sorptionsmittel und einer zweiten Menge Kohlendioxid,
Überführen eines Teils des kalzinierten zweiten Ausgangsmaterials, das das zweite kohlendioxidarme Sorptionsmittel enthält, zu dem Karbonator (2) und Ziehen des anderen Teils des kalzinierten zweiten Ausgangsmaterials als Spülstrom aus dem zweiten Kalzinator.

8. Verfahren gemäß Anspruch 7, dadurch gekennzeichnet, dass des erste und das zweite kohlendioxidreiche Sorptionsmittel CaCO₃ umfassen und das erste und das zweite kohlendioxidarme Sorptionsmittel CaO umfassen.

9. Verfahren gemäß Anspruch 7, gekennzeichnet durch Überführen des anderen Teils des kalzinierten zweiten Ausgangsmaterials, das das zweite kohlendioxidarme Sorptionsmittel enthält, aus dem zweiten Kalzinator (15) zu einem Ofen (3) für die Zementherstellung.

Revendications

1. Système de capture de carbone comprenant
un carbonateur (2) conçu pour adsorber du dioxyde de carbone à l'aide d'un premier sorbant pauvre en dioxyde de carbone (13) et d'un second sorbant pauvre en dioxyde de carbone (17) pour produire un sorbant riche en dioxyde de carbone (16),
un apport de matière première (4) contenant un sorbant riche en dioxyde de carbone,
un premier four de calcination (1) conçu pour calciner l'apport de matière première (4) par décomposition thermique, en le premier sorbant pauvre en dioxyde de carbone (13) et une première quantité de dioxyde de carbone,
une liaison (13) entre le premier four de calcination (1) et le carbonateur (2) pour le transfert au moins du premier sorbant pauvre en dioxyde de carbone vers le carbonateur (2),
caractérisé en ce qu'il comprend en outre
un second four de calcination (15) conçu pour décomposer thermiquement le sorbant riche en dioxyde de carbone (16) produit dans le carbonateur en sorbant pauvre en dioxyde carbone et une seconde quantité de dioxyde de carbone,
une liaison (16) entre le carbonateur (2) et le second four de calcination (15) pour le transfert au moins du sorbant riche en dioxyde de carbone vers le second four de calcination (15),
une liaison (17) entre le second four de calcination (15) et le carbonateur (2) pour le transfert du second sorbant pauvre en dioxyde de carbone (CaO) vers le carbonateur (2) et
un moyen (18) pour le soutirage d'un flux de purge de sorbant pauvre en dioxyde de carbone à partir du second four de calcination.

2. Système de capture de carbone selon la revendication 1, caractérisé en ce qu'il comprend en outre
un four (3) pour la production de ciment,
une liaison (18) entre le second four de calcination (15) et le four (3) pour le transfert du flux de purge de sorbant pauvre en dioxyde de carbone vers le four (3).

3. Système de capture de carbone selon la revendication 1, caractérisé en ce qu'il comprend en outre
un réchauffeur (21, 22) pour la matière première à calciner.

4. Système de capture de carbone selon la revendication 1, caractérisé en ce qu'il comprend en outre
un échangeur de chaleur solide/solide (31) pour le chauffage du second sorbant riche en dioxyde de carbone allant du carbonateur (2) vers le second four de calcination (15) par refroidissement des premier et second sorbants pauvres en dioxyde de carbone allant du premier four de calcination (1) et du second four de calcination (15) respectivement vers le carbonateur (2).

5. Système de capture de carbone selon la revendication 2, comprenant en outre
un échangeur de chaleur (48) pour le refroidissement de clinker évacué du four (3) par chauffage d'oxydant frais et
au moins une liaison (42, 43) de l'échangeur de chaleur (48) vers :

- le four (35), pour l'introduction de l'oxydant chauffé dans le four (35), et/ou

- un système de séchage de combustible.

6. Système de capture de carbone selon la revendication 5, dans lequel au moins l'une des liaisons (42) vers le four (35) est pourvue d'un échangeur de chaleur (40) pour le réchauffage de l'oxydant introduit dans le four (35) par refroidissement de gaz effluent évacué du four (35).

7. Procédé pour la capture de dioxyde de carbone comprenant
l'introduction d'une première matière première contenant un premier sorbant riche en dioxyde de carbone dans un premier four de calcination (1),
au niveau du premier four de calcination (1), la décomposition thermique du premier sorbant riche en dioxyde de carbone en un premier sorbant pauvre en dioxyde de carbone et une première quantité de dioxyde de carbone,
l'introduction de la première matière première calcinée contenant le premier sorbant pauvre en dioxyde de carbone dans un carbonateur (2),
au niveau du carbonateur (2), l'adsorption d'un dioxyde de carbone à partir de gaz effluent ce qui produit une seconde matière première contenant un sorbant riche en dioxyde de carbone,
caractérisé par
l'introduction de la seconde matière première contenant le second sorbant riche en dioxyde de carbone dans un second four de calcination (15),
au niveau du second four de calcination (15), la décomposition thermique du second sorbant riche en dioxyde de carbone en un second sorbant pauvre en dioxyde de carbone et une seconde quantité de dioxyde de carbone,
le transfert d'une partie de la seconde matière première calcinée contenant le second sorbant pauvre en dioxyde de carbone vers le carbonateur (2) et le soutirage à partir du second four de calcination en tant que flux de purge de l'autre partie de la seconde matière première calcinée.

8. Procédé selon la revendication 7, caractérisé en ce que
les premier et second sorbants riches en dioxyde de carbone comprennent du CaCO₃ et les premier et second sorbants pauvres en dioxyde de carbone comprennent du CaO.

9. Procédé selon la revendication 7, caractérisé par
le transfert de l'autre partie de la seconde matière première calcinée contenant le second sorbant pauvre en dioxyde de carbone du second four de calcination (15) vers un four (3) pour la production de ciment.

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